如何通过CSS改变双图级数的颜色

<style>
    .dual-number {
        color: red;
    }
</style>

<span class="dual-number">双图级数</span>

<style>
    .dual-number {
        background-color: blue;
        color: white;
    }
</style>

<span class="dual-number">双图级数</span>

<style>
    .dual-number {
        background: linear-gradient(to right, red, blue);
        -webkit-background-clip: text;
        -webkit-text-fill-color: transparent;
    }
</style>

<span class="dual-number">双图级数</span>